Buying Tuning Parts .. Confused

I’m new to mini engine tuning.
I need to buy parts and have parts machined but have read on here that the two main suppliers frequently have quality and service issues.

The one in particular that I always considered the watchword in Mini Parts back in the 70’s seems to attract the most criticism.( although I had a 1275 S engine built by them that never ran well and constantly “pinked” no matter what I did to prevent it)

So my confusion is ... where do I source the several thousand pounds worth of parts and service that I need.

Bought an ex RSP 1275cc carb’d engine with box that I want to re-build to a 1330cc 100 bhp / 100 ft/lbs motor like the one in Bill Sollis ‘ dvd.
Should I have the existing head modified or buy a new one? .... it’s a small valve head.

You are most welcome to ask away to your heart's content here on the Forum on what I'm about to suggest, however if I can suggest, get yourself a few books on the subject and read up in them, even if you are not intending to get your hands dirty doing the work, but I suggest this so as you can gain a broader understanding of the principals involved and the finer points of theory for Engine Tuning that I don't think you'd gain as quickly from the forum (and no disrespect to our forum or our fine members in that).

While any book you buy will be dated in regards to specific parts, the principals remain the same.

This should give you a firmer standing on the Pros and Cons or various set ups so that (hopefully) you'll be more likely to land closer to what you want without having to do it a few times over.

2 Books I can suggest are Des Hamils Power Tuning 1275 and David Vizards Tuning the A Series Engine.

Hiya
Thanks all for replies.
Apologies if some of my recent posts seem a bit naive .... (also trying to build my post count so that I can use all parts of the forum)
Have been building and successfully racing (off road and drag) performance / race air cooled VW engines for over 20 years and am a reasonable machinist and had a small business as a result of above re building , turbo modifying , race and road tuning mostly sidedraft and downdraft dual barrel DellOrto and Weber carbs. Lot of very quick cars still running with my stickers on them.
Had minis in my youth going back to late 60s

It’s my belief that it’s best to ask mini people who know much better than me about best way to go hence some of the noobie questions.
Concepts are pretty much the same for tuning engines whether a/c VW boxer or A Series but methodology and supplier base isn’t.

I also bought a 1275cc carbed engine from a scrapped RSP car which is the one I want to modify more extensively and it’s that which will need machining and parts ... but mostly advice.
Eg ... alloy ratio rockers or cast (forged?) steel ..... new head or modified existing head etc
After watching the Bill Sollis DVD I was intent on going to 1380cc but an experienced tuner on here explained that meant offsetting bores whereas 1330cc didn’t detract much from performance and block could be relined again.
Stuff like that

Unless the car is for real competition, don't get too obsessed with maximum bhp. What you want is an engine with really good mid-range torque and the ability to pull well whilst having reasonable driveable final drive ratio. Once you start chasing peak bhp you end up with an engine which needs to rev to around 6800 rpm and with poor low-end torque and a narrow power band. This then leads to the need for a close ratio gearbox and then first gear is so high that a low final drive ratio is necessary to avoid having to slip the clutch too much. The end result is a top gear with low cruising speed or very high revs required to cruise at motorway speeds.

As an example, my Cooper 'S' has around 100+ bhp. But it has a 286 cam, a SC CR gear set and thus a 3.9:1 final drive ratio, This gives me around 14 mph/1000 rpm in top gear, so 70 mph is 5000 rpm. Max power is at 6400 and so when using full performance I change up at around 6700 rpm. Frequent re-builds are necessary and it is a 'cammy' little beast..

However with, say, a 266 cam you can easily get 85 to 90 bhp and the mid-range torque is fantastic. There are other cams which do about the same. You can then run my favourite FDR which is a 3.44:1 as found in the original 1275 'S'. Top gear is then around 16.5 mph/1000 rpm.

With regard to sourcing parts I generally buy from Mini Spares. I've had issues at the 'other lot', but MS do put a lot of effort into their part supplier selection. Quality can always be an issue with low-volume parts and price is also an issue with a lot of classic car owners. Simon and Gary at Mini Spares at Potters Bar and Richy at Mini Spares North are both very helpful and it is a good idea to call them if you have any questions.

Just ordered some parts from Richy earlier today. Nothing exotic, new rear subframe mounts, new steering rack boots and a much needed pair of seat bracket extensions.
He s a really nice guy who spent quite a lot of time talking to me about minis.
He also felt I should keep the car as original as possible.
DavidR